1. Field of the Invention
The present invention relates to a saw blade machine provided with a saw blade such as a saw chain and a reciprocating blade, and to a trimmer provided with a saw chain. More particularly, the present invention relates to a saw blade machine and a trimmer in which a section including a lubricating oil pump for automatically supplying a lubricating oil to a saw blade during operation is reduced in size.
2. Description of the Related Art
In a saw blade machine such as a chain saw, a trimmer and an edger for cutting trees and branches and for trimming an edge of a lawn, it is necessary to suitably supply a lubricating oil to the saw blade so as to prevent the saw blade burn-up during operation.
A device for supplying a lubricating oil to the saw chain in the conventional chain saw comprises a worm fixedly mounted to a predetermined section of an engine crankshaft rotatively driving the saw chain, a worm wheel meshed with the worm and mounted onto a periphery of a plunger, and a single twin-helical guide groove formed on the periphery of the base portion of the plunger and having a positioning pin inserted therein. With the rotation of the crankshaft, the plunger is reciprocally displaced in the axial direction while rotating in the circumferential direction to increase or decrease a capacity of a pump room so that the lubricating oil is discharged from the pump room to supply it to the saw chain.
According to a chain saw disclosed in U.S. Pat. No. 4,353,163, a rotation power of an engine for driving the saw chain is transmitted to an input shaft of a vane pump through spur gears meshed with each other so that the lubricating oil is discharged from the vane pump to supply it to the saw chain.
In U.S. Pat. No. 4,884,340, there is disclosed a thumb-operated pump, and an operator suitably operates the pump to supply the lubricating oil from the pump to the saw chain.
According to a manual type lubricating oil pump, the operator is required to manually operate the lubricating oil pump while performing a cutting operation. This may result in an increase of the labor, and tends to burn up the saw chain when the operator forgets the manual operation for supply of the lubricating oil. Further, the manual type lubricating oil pump is likely to result in a deterioration in stability of operation and an unforeseen accident may be also apprehended.
According to the chain saw employing an automatic drive lubricating oil pump such as a plunger pump and a vane pump, an input shaft of the lubricating oil pump is provided separately from a drive shaft members for driving the saw blade and a section including the drive shaft members and the lubricating oil pump is increased in size. In addition, since the plunger pump and the vane pump include a large number of parts and high accuracy is required for manufacturing these pumps, efficiency in manufacturing and mounting these pumps is reduced.